1. Field of the Invention
The present invention relates to a facsimile apparatus, copier, or other image data processing apparatus using an optical disk recording medium and a method of data transmission and method of data reproduction in a facsimile apparatus.
2. Description of the Related Art
One known type of facsimile apparatus is the facsimile apparatus called the storage-type facsimile apparatus.
In such a storage-type facsimile apparatus, the content is read from the document to be transmitted, the image data to be transmitted is compressed and stored once in a memory, then immediately after storage or at a designated time after storage, the stored compressed image data for transmission is sent as a "preset transmission".
Such a storage-type facsimile apparatus usually includes a semiconductor memory, for example, a dynamic random access memory (DRAM). When a DRAM is used, however, there are limits to the capacity of the data which can be stored. Usually, if the amount of the data to be transmitted becomes too large, it is sent divided into several transmission sessions. For example, assuming the amount of data of an A4 size (296 mm.times.210 mm) document to be 50 KB and use made of a 1 MB DRAM, the number of pages which can be stored at one time would just be about 20 pages. Accordingly, in a storage-type facsimile apparatus, an A4 size document of 50 or 100 pages would be divided and sent over several transmission sessions.
If divided for transmission, one stored portion of the image data would be sent out, then the next portion would be stored and therefore the telephone link released, so when trying to send the next portion of the image data, another facsimile apparatus might intervene and send its own transmission to the destination facsimile apparatus, so the problem would arise of the desired content of the transmission not being consecutively received by the other party. As a result, there would be the trouble of separating the results received at the destination facsimile apparatus due to the reception of several transmissions from other facsimile apparatuses at the destination facsimile apparatus.
When performing "preset transmission" for storing documents for transmission in a storage-type facsimile apparatus and transmitting them at a designated later time, it is necessary to store the entire content of the document at one time, but if the document contains too many pages, the problem is encountered of an inability to perform "preset transmission" due to the limits of the storage capacity.
Further, when the facsimile paper has run out and the image data received cannot be printed out, one method used is to store the data in the memory built into the facsimile apparatus as "automatic alternate reception", but in this case too the problem is encountered of the alternate reception not being able to be completely carried out due to limitations in the memory capacity if the number of pages received becomes too large.
In this case, the sender has to be asked to retransmit, which is both time consuming and bothersome to the other party. In particularly, when receiving a transmission from another country, the troublesome work of asking for retransmission to the foreign sender becomes necessary.
On the other hand, there has been proposed a facsimile apparatus which has a memory built into it, stores the compressed image data it receives in the memory once, then displays the image data once on a display apparatus instead of constantly printing it out, so does not print out or record received information of a transitory nature, but prints out only information which the receiver wishes to record and keep (for example, in Japanese Unexamined Patent Publication (Kokai) No. 2-231868).
With such a facsimile apparatus, there is the advantage that received information of a transitory nature can be checked on the display without being printed out, plus, like in the past, it is possible to print out a hard copy of information desired to be kept as a record.
There are currently already known copiers which record the copied information on removable floppy disks. That is, the method of paperless storage of the content of documents is known in the field of copiers.
Like with copiers, it would be convenient for facsimile apparatuses to be able to record the received information on floppy disks or other removable recording media, but this has not yet been proposed for facsimile apparatuses.
One method which may be considered for solving the problem of the limited memory capacity mentioned above is to increase the capacity of the memory built into the facsimile apparatus. The memory capacities of semiconductor memories, for example, DRAM's, have grown tremendously and these devices have become low in price as well.
When image processing and compressing the content of A4 size documents, however, a memory capacity of 50 KB or so is required for an A4 size page. Considering the trend toward paperless documents mentioned above and assuming a memory capacity able to store 2000 A4 size pages of documents per month, the memory capacity would become 100 MB. It is not practical economically, however, to mount a DRAM of a capacity of as much as 128 MB. Further, DRAM's are not suited to removal from facsimile apparatuses, which is a requirement in the trend toward paperless documents.
If facsimile apparatuses, like copiers, are provided with removable floppy disks, it would be possible for them to store the contents of documents without paper and also the received image data could be reproduced at any time using not only the facsimile apparatus receiving it, but other facsimile apparatuses or new image data reproduction apparatuses.
Floppy disks, however, have a capacity of at most 1 to 2 MB at the present time. Like with semiconductor memories, if the received data becomes very large, it cannot be accommodated on a single floppy disk, making insertion of another floppy disk necessary.
Usually, a human operator has to exchange the floppy disks, which complicates the work. Of course, it is possible to install a number of floppy disk drives in a facsimile apparatus, but this is not practical. At the same time, consideration may be given to an automatically exchanging floppy disk drive, but it is not realistic to mount such a complicated piece of apparatus in a facsimile apparatus.
There is the possibility of using a hard disk with a capacity of for example 100 MB or 200 MB in place of a semiconductor memory or floppy disk. Usually, however, a hard disk is used built in to an apparatus and not removable from the same. Of course, removable hard disks are known, but these hard disks are limited and high in price and there it is not practical to use hard disks for facsimile apparatuses, copiers, etc.
One means for increasing the storage capacity and realizing interchangeability is to make use of magnetic recording medium such as cassette tapes which can continuously record and reproduce information, but such magnetic recording medium are not random access memories, so there is the problem that time is taken to retrieve the desired information.
Sometimes it is desired to send the same transmission to several parties, for example, several branches. With the currently known facsimile apparatuses, it is necessary to set the document for transmission in the facsimile apparatus and go through the transmission procedures for each destination, so the work efficiency is poor.
In this way, the current facsimile apparatuses and copiers and other image data processing apparatuses have had problems in the limited storage capacity and interchangeability.